A hybrid vehicle is publicly known in which a battery storing electric power to be supplied to a driving motor is disposed in a luggage compartment located behind a rear seat. In the hybrid vehicle, the battery needs to be protected against shock in case of a vehicle crash. However, providing any particular reinforcement for battery protection will disadvantageously increase the weight of the vehicle body, resulting in degraded driving performance. A technique of solving such disadvantage is disclosed in, for example, Japanese Patent Laying-Open No. 2007-8443.
With a vehicular power supply device disclosed in Japanese Patent Laying-Open No. 2007-8443, electric power from a battery is supplied to a motor that drives the vehicle. This vehicle includes a battery box that houses the battery therein, a rear seat, right and left side frames extending in the front-to-rear direction of the vehicle, a cross member connecting the right and left side frames on the bottom face of the front portion of a seat cushion of the rear seat, and a fuel tank disposed in the space enclosed by the right and left side frames, the cross member and the bottom face of the seat cushion. The right and left side frames each have a portion curved upwardly at a position that corresponds to a rear wheel house located behind the rear seat. The right and left ends of the battery box are connected between the apexes of the curved portions. Part of the battery box projects upwardly from the apexes of the curved portions.
With the vehicular power supply device disclosed in Japanese Patent Laying-Open No. 2007-8443, the battery box that houses the battery therein is mounted between the right and left side frames. This not only allows the battery box to be protected by the right and left side frames against shock in case of a side crash, but also ensures the largest capacity of the battery box. Further, connecting the right and left ends of the battery box to the right and left side frames, respectively, not only allows the battery box to be mounted firmly on the vehicle body, but also improves the rigidity of the right and left side frames because of the presence of the battery box.
However, in the vehicular power supply device disclosed in Japanese Patent Laying-Open No. 2007-8443, part of the battery box projects upwardly from the apexes of the curved portions of the right and left side frames. This reduces the space located behind the rear seat in a vehicle compartment (luggage compartment), resulting in degradation of interior comfort.